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3/2
PULLDOWN - Since film is usually shot at 24 frames per second
and video has 30 frames per second, we need to make up 6 frames per
second when transferring film to video. This is done by adding an
extra field to every other film frame, (there are 2 fields per video
frame), resulting in a field sequence of AA, BBB, CC, DDD etc. This
process is called 3/2 pulldown. There is no 3/2 pulldown when the
film was shot at 30fps in NTSC, or 25fps in PAL because in these
cases the film and video are running at the same rate, (1 film frame
per 1 video frame).
AATONCODE
- (similar in concept to Arri FIS). A code exposed along the edge of
the film at the same time the image is exposed. AatonCode contains
time code, shoot date and camera I.D. information. Only certain
cameras can expose this code. AatonCode contains the same time code
as that being recorded simultaneously on the audio deck. During film
transfer, AatonCode is decoded by a reader attached to the telecine,
(Keylinker). The audio locks to the matching AatonCode and
automatically syncs with the picture. This eliminates the need for a
slate during shooting since sync can be determined at all times via
the AatonCode. (A visual/audio slate such as a clap-board or
smart-slate can be used as a back-up.)
ANALOG
/ DIGITAL - An example of analog: a plucked guitar string
vibrates the air around it. These air waves in turn vibrate a small
membrane in a microphone. This membrane translates those vibrations
into fluctuating electronic voltages. During recording to tape, these
voltages charge magnetic particles on the tape, which when played
back will duplicate the original voltages, and hence the original
sound. Recording pictures works similarly, except that instead of air
vibrating a membrane, fluctuating light strikes an electronic
receptor that changes those fluctuations into voltages. Analog
describes real world sound and images that have been translated into
continually changing electronic voltages. In the digital world, the
same varying voltages are sampled or measured at a specific rate,
(e.g. 48,000 times a second or "48K". Because of
sampling, a digital signal is segmented into steps that define the
overall quality of the signal. A signal sampled at 48K is better than
one sampled at 44.1K. These samples are represented by bits, (0s and
1s) which can be processed and recorded. The more bits a sample has
the better the picture or sound quality, (e.g. 10 bit is better than
8 bit). A good digital signal will have a high number of samples,
(sampling rate) and a high number of bits, (quantizing). Digital
processing clears the way for multiple, perfect copies or "clones",
because it is the bits that are copied instead of the analog voltages.
ASPECT
RATIO - Refers to the ratio of width to height of an image.
Standard television aspect ratio is currently four units wide by
three units high, or 4:3. Super 16mm aspect ratio is 15:9, or said
another way, 1.66 units wide for every 1 unit high, otherwise listed
as 1.66:1 (read 1.66 to 1), or simply ìone-six-sixî.
High definition television (HDTV) is slightly wider at 16:9 or 1.77
units for every 1 unit high ("one-seven-seven"). Even wider
still are theatrical projections with common aspect ratios of 1.85
and 2.35. An entire wide screen image displayed on a regular
television will have a black band at the top and bottom. This is
called letterbox.
CENTER
TRACK TIME CODE - A time code signal recorded along the center
of a 1/4" audio tape. This signal is used as a locating tool
when syncing audio to film. It is also used to make sure the tape
plays back at the exact speed it was recorded in the field, (this is
called resolving). Often, time code is striped onto tapes that have
Neopilot before a film transfer session begins.
COLOR
CORRECTION - This term might be better thought of as "color
enhancement" or "color manipulation". Why do film and
video images need color correction?
A)
Film has a much wider contrast and color range than video. Color
correction allows the colorist to adjust these characteristics to
meet the producers needs.
B)
Shooting situations are not always ideal and are often spread out
over time. Color correction provides a controlled environment to
match scenes from differing conditions.
C)
Sometimes a special effect is needed where unusual colors or textures
are desired.
The
following are terms used to describe the level of color correction
used for a color correction session:
Scene-by-Scene
- The highest level of color correction. The colorist uses any
available technique and makes as many color corrections as necessary
to create the best possible image from a film or tape source. In
addition, the colorist matches each scene to the rest of the project
to achieve an overall look consistent with the desires of the
producer. The resulting transfer will be suitable for any end use.
Best
Light - The middle level of color correction. Each scene is color
corrected but not matched to any other scene. The colorist will stop
as often as necessary to adjust for scene or lighting changes. The
resulting transfer will be suitable for stock libraries, editing,
(especially when the edit source image quality must be appealing),
and final scene-by-scene tape-to-tape color correction. (Only used
during film-to-tape-transfer.)
COLOR
TEMPERATURE - A measurement of the color tint of a white light
source. This is expressed in degrees Kelvin (K). The bluer or "cooler"
the light the higher the number, the redder or "warmer" the
light the lower the number. A normal light bulb is around 3200K,
normal daylight is around 6000K. Television monitors are on the cool
side with a U.S. standard set at 6500K.
COMPOSITE
PRINT - A film print with a sound track printed on the film.
This can be a magnetic sound track, but most often is an optical track.
DAILIES
- Originally this term referred to the "rushes" or
"daily" workprint created overnight for a feature film
director/crew to view in the morning, so they could see if they got
their desired scenes before striking the sets. In the video world
"dailies" came to mean a quick transfer of original
negative so that a spot could be viewed and edited on a 3/4"
system etc. before returning to a telecine suite for the real
transfer session. Currently dailies also encompass transfer of
original documentary negative to video for off-line editing purposes.
Later this footage might return to telecine for a tape-to-tape color
correction session. The overall similarity of these scenarios is that
the dailies are not the final color correction for the footage, but
rather a way to be able to view and edit the material before bringing
a cut-down version back to telecine for more critically matched corrections.
EDGE
NUMBERS / KEY NUMBERS - These numbers are printed by the
manufacturer at 1 foot intervals, (35mm) and 1/2 foot intervals,
(16mm), on the edge of raw film stock . They act not only as a
footage counter and location marker on the stock, but also contain
film type and manufacturing batch codes. Edge numbers / key numbers
on a workprint copy are used to locate scenes from the original
negative. See also Keykode, a bar-coded format of key numbers.
FLEX
FILE - A computer generated file that keeps track of 3 different
codes and other information at any given point. Most importantly,
this file establishes the relationship of video time code to film
Keykode, but can also include audio time code, (or AatonCode). Flex
files are used in off-line systems, or by a film lab to trace a video
EDL back to original camera negative (via Keykode), so that the film
can be cut into a finished print. In addition, select reels for a
final film-to-tape color correction can also be made. Flex files also
have the ability to log slate information such as "scene",
"take", "camera roll", or "audio roll",
at each camera stop. Most often only the "headpunch" of
each camera roll is logged to establish the video time code to
Keykode relationship for each roll. (If AatonCode is on the film, all
camera stops can be logged automatically).
KEYKODE
- Eastman Kodak encodes edge numbers into a bar code format called
Keykode. These bar codes are printed by the manufacturer at 1/2 foot
intervals on the edge of 16mm negative, and 1 foot intervals on 35mm,
along with edge numbers or ìkey numbersî that are
readable by eye. Keykode allows machines to electronically read key
numbers as the film passes through a reader attached to the Rank.
Keykode / key numbers act as a sort of time code for film, providing
location information as well as film stock type and batch codes.
LATENT
EDGE NUMBERS - Edge numbers that have printed through from one
film stock to another, e.g. from negative to a workprint copy.
MAG
FOLLOWER - The machine that plays mag track audio. This machine
interlocks with the telecine for sync audio, and can handle 35mm 3
& 4 track formats as well as 16mm 1 & 2 track formats.
MAG
TRACK - Audio track recorded on 35mm or 16mm oxide coated stock.
Mag stock has the same dimensions and sprocket holes as film stock.
This format is not used for original field recordings, but rather as
a secondary or mix use. For those using flatbed editing systems,
original field audio is dubbed to mag stock, then the workprint
(picture), and mag audio are edited in unison. 35mm mag offers 3 or 4
track formats, while 16mm offers 1 or 2 tracks.
MAG
STRIPE - Refers to a thin strip of magnetic oxide on the edge of
picture film, that contains a single audio track. A small audio head
attached to the telecine reads the audio during the transfer.
MATCHBACK
- The process of cutting camera original film using a video EDL.
Currently, more editors are choosing to work on a non-linear video
off-line system like the ìAvidî instead of a flatbed
editing system like the "Steenbeck". This means all film
and audio must be transferred to a video format for input into the
off-line system. After the off-line editing is complete, a producer
may wish to return to the camera original film to either assemble a
print for projection, or to assemble reels of selected takes for a
scene-by-scene color correction, (before the final on-line). To
accomplish this match back to the negative, a Flex File is generated
during the initial transfer, to mark video time code and film Keykode
relationships at the beginning of each camera roll.. This provides a
list so that a video EDL can be translated into a Keykode EDL which
the negative conformers use to cut the film.
NAGRA
- A 1/4" audio machine made by "Nagra-Kudelski" of
Switzerland. Those who record 1/4" audio in the field use Nagras
almost exclusively. The pilot system allows for the playback of audio
at the precise speed it was recorded on location. Studio Nagras can
handle both neopilot (more common), and F.M. pilot, as well as
center-track time code at all standard speeds, (15ips, 7.5ips,
3.75ips). They are stereo, (two track) decks that can be synced with
the telecine, VTR's, or used as a source deck in an edit suite.
NOISE
REDUCER / ENHANCER - The magic box in telecine that reduces
electronic "noise" and film grain, while simultaneously
enhancing or sharpening the picture. Both attributes can be dialed in
to varying degrees. The telecine signal always passes through this
box, with "normal" settings for noise reduction and
enhancement in place.
OPTICAL
TRACK - An audio track in the form of a stripe down the side of
a film print. A light source on the projector or telecine shines
through this stripe. Because of changes in the pattern of the optical
track, the light is modulated as it strikes an electronic receptor,
which translates the information into an audio signal. A film print
with an optical track is also referred to as a composite print, or
called a print SOF which stands for "sound on film". Most
release prints have optical sound tracks, e.g. movies at theaters.
PILOT
- A signal recorded by Nagras on 1/4" tape to ensure that audio
will play back later at precisely the same speed it was recorded in
the field. When a playback Nagra locks onto this signal, the pilot is
being resolved, or played back at the proper speed so that the sound
will stay in sync with the picture. There are two types of pilot in
use. The more common version is neopilot which is used on mono audio
recordings only. F.M. pilot is used with 2-track or stereo
recordings. To be able to sync audio in telecine, time code is needed
on the tapes instead of pilot. Neopilot tapes are striped with center
track time code, whereas F.M. pilot tapes need to be dubbed to
another audio tape because of technical reasons. All striping and
dubbing should happen before the transfer session.
SLATES
- A visual marker used during filming to provide production and scene
information. Also a visual and audible marker for syncing picture and
audio later in post production. There are several different methods
of slating: A smart slate provides a readable time code display on a
clapper board. This time code is the same that is being recorded
simultaneously on the audio tape. By stopping on any frame and
reading the displayed time code, one can find that exact point on the
audio tape, then lock the audio to the film for sync sound. A bloop
slate is basically a box with a light bulb or a 2 digit number
display. When a button is pressed the light(s) illuminate and a tone
is recorded onto the audio tape. By lining up the light with the
sound beep, sync is achieved. Clap sticks are the most traditional,
with the clap of the wood as the sync reference. Of these methods,
smart slates are the fastest and most accurate. Head slates, those
that appear at the beginning of a sound take, are far preferred over
tail slates in which the marker is provided at the end of the take,
(usually with the slate upside down to denote a tail mark).
SYNC
TAKES - Segments of film with simultaneously recorded audio that
are marked with a slate so that they can be easily synced or
"locked" together in post production.
TELECINE
- The machine used to transfer film to videotape. The telecine acts
as an electronic film projector, shining light through the film, then
turning it into an electronic signal. After color correction, the
signal is formed into a video picture that can be recorded onto a videotape.
TIME
CODE - An electronic code recorded on audio and videotape that
acts as a location marker or time reference for the recorded
material. Professional video systems rely on time code for cueing and
editing. A video EDL consists mainly of time code ìinsî
and ìoutsî to direct an editor to the beginning or end
of scenes.
TLC
- Time Logic Controller, the editing system for telecine. This
machine controls the telecine and up to four VTR's simultaneously
with field-accurate editing and full 3/2 pulldown management.
ULTRASONIC
FILM CLEANER - A device that runs film through a heated bath of
fluid which is vibrated at ultrasonic frequencies. Jets of fluid and
swirling buffers add to the cleaning power. Finally, the film is run
through a heated air dry system before winding onto a take-up reel.
USER
BITS - A section of the time code signal that provides 8 digits
which can be programmed by the user for organizational purposes,
(e.g. show codes or tape reel numbers). User bits are limited to the
numbers 0-9 and letters A-F, and usually remain static, (as opposed
to running like time of day).
VARI-SPEED
- Refers to film or tape running at any non-standard speed.
WETGATE
- A device that allows film to be projected through a chamber of
liquid in order to produce a scratch and dirt free transfer or print.
A scratch or mark in the film is visible because light refracts on
the edges of the scratch itself. As light passes through the image
using the Wetgate system, fluid fills the scratch and stops the
refraction so that the imperfection is invisible, (some scratches on
the emulsion side may not be removed). A Wetgate is a good problem
solver, but has a few disadvantages. Because the film passes through
a fluid, and needs to dry before winding on a take up reel, high
speed winding is not feasible. Also, the fluid used in these gates is
an ozone depleter, and very expensive since its production has been
restricted by the government. See also Digital Wetgate.
WILD
SOUND - Sound that isn't meant to sync with picture, e.g. room
tone, birds chirping, flags waving in the wind etc. This sound is
used as background or as ambience. Wild sound might also include
voice-over audio that was recorded without picture, e.g. off camera
interviews or spot disclaimers.
X-Y-ZOOM
- A feature of the telecine that allows the image to be moved
left or right (X), up and down (Y), or in and out (Zoom). Although
the picture can be degraded if zoomed in too far, it is better for an
image to be re-framed in telecine rather than with a DVE in edit. |
